US5787883A - Spring-free pressure regulator with structure isolating exhaled air from valve - Google Patents

Spring-free pressure regulator with structure isolating exhaled air from valve Download PDF

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Publication number
US5787883A
US5787883A US08/376,084 US37608495A US5787883A US 5787883 A US5787883 A US 5787883A US 37608495 A US37608495 A US 37608495A US 5787883 A US5787883 A US 5787883A
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US
United States
Prior art keywords
valve
pressure
chamber
mixing chamber
pressure regulator
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US08/376,084
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English (en)
Inventor
Robert L. Cramer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mission Systems Davenport Inc
Original Assignee
Litton Systems Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Litton Systems Inc filed Critical Litton Systems Inc
Priority to US08/376,084 priority Critical patent/US5787883A/en
Application granted granted Critical
Publication of US5787883A publication Critical patent/US5787883A/en
Assigned to CARLETON LIFE SUPPORT SYSTEMS, INC. reassignment CARLETON LIFE SUPPORT SYSTEMS, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: LITTON SYSTEMS, INC.
Anticipated expiration legal-status Critical
Assigned to COBHAM MISSION SYSTEMS DAVENPORT LSS INC. reassignment COBHAM MISSION SYSTEMS DAVENPORT LSS INC. CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: CARLETON LIFE SUPPORT SYSTEMS INC.
Expired - Lifetime legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A62—LIFE-SAVING; FIRE-FIGHTING
    • A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
    • A62B9/00—Component parts for respiratory or breathing apparatus
    • A62B9/02—Valves
    • A—HUMAN NECESSITIES
    • A62—LIFE-SAVING; FIRE-FIGHTING
    • A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
    • A62B7/00—Respiratory apparatus
    • A62B7/02—Respiratory apparatus with compressed oxygen or air
    • A62B7/04—Respiratory apparatus with compressed oxygen or air and lung-controlled oxygen or air valves
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/7722—Line condition change responsive valves
    • Y10T137/7781—With separate connected fluid reactor surface
    • Y10T137/7793—With opening bias [e.g., pressure regulator]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/7722—Line condition change responsive valves
    • Y10T137/7781—With separate connected fluid reactor surface
    • Y10T137/7793—With opening bias [e.g., pressure regulator]
    • Y10T137/7803—With protective separator

Definitions

  • This invention relates to a breathing apparatus for use in hazardous environments and more particularly to a gas mixing pressure regulator for supplying breathable gas to the breathing apparatus.
  • a typical breathing apparatus generally comprises a face mask, a supply of pressurized oxygen/nitrogen mixture, an inhalation tube extending from the pressurized supply to the face mask, an exhalation tube that receives exhaled air which is then directed to an exhalation chamber and through a scrubber assembly to remove carbon dioxide from the exhaled air.
  • the carbon dioxide-free air is then mixed with a proper mixture of oxygen/nitrogen and is recirculated back through the system as breathable air.
  • a pressure regulator is provided for mixing the carbon dioxide-free exhaled air with the proper mixture of oxygen/nitrogen from the pressurized supply for recirculation back through the face mask as breathable air.
  • Prior pressure regulators required the use of mechanical springs for opening and closing valves for properly mixing gas from the pressurized supply and exhaled air. Such springs are subject to not only failure but energy loss and instability requiring the need for a by-pass in case of a malfunction. In the event of failure of the springs within the regulator, unregulated breathable air could flow from the pressurized supply directly to the face mask. Conversely, failure of the opposing spring can prevent flow of breathable gas to the mask. This latter condition must, by regulation, be prevented by an elaborate by-pass mechanism which this invention eliminates.
  • a breathing diaphragm is biased against an external spring for moving an inlet for supplying pressurized air to the face mask.
  • Such springs have been found to be unstable and tend to move away from the lever during exhalation causing a delay in the response to the need for breathable air by the user.
  • a pressure regulator for a breathing apparatus of this invention has a mixing chamber for providing a proper mixture of enriched stored oxygen/nitrogen gas and exhaled gas which has been scrubbed of carbon dioxide, a first inlet port to supply enriched stored gas to the mixing chamber, a second inlet port to supply carbon dioxide-free exhaled gas to the mixing chamber, and a mixing tube for supplying the mixed gases to a face mask.
  • a pressure responsive demand valve is provided to open the first inlet to supply enriched stored gas to the mixing chamber.
  • the pressure demand valve includes a sliding stem for opening and closing the first inlet port actuated by a pivotable lever in response to a pressure sensitive diaphragm. The valve is pneumatically isolated from the mixing chamber to prevent moisture from the exhaled air and cleaning solution from contaminating the valve.
  • Objects, features and advantages of this invention are to provide an improved pressure regulator for a breathing apparatus that does not utilize mechanical springs, eliminates the need for a by-pass, and utilizes a valve that is pressure responsive, in which the lever and sliding valve are isolated from contaminants and cleaning solution, is more efficient, is more reliable, rugged, stable, durable economical to manufacture and assemble and in service has a long useful life.
  • FIG. 1 is a schematic drawing of the breathing apparatus embodying the present invention.
  • FIG. 2 is an enlarged cross-sectional view of the pressure regulator.
  • FIG. 1 illustrates a breathing apparatus 10 embodying this invention having a face mask 12, an inhalation tube 14 and an exhalation tube 16, both of which are connected to a breathable air supply contained within a carrier pack 17 which can be worn on the back of the user.
  • the source of pressurized stored gas 18 is provided within the carrier pack 17 and contains an oxygen/nitrogen mixture, preferably at a ratio of 38% oxygen.
  • the oxygen rich gas is supplied to the face mask 12 via an on/off valve 20, high pressure hose 22, pressure reducer 24, connector hose 25, pressure regulator 26, inhalation tube 14 and the face mask 12.
  • a pressure indicator 28 is interposed via a T connection in connector hose 25.
  • exhaled air travels from the face mask 12 through the exhalation tube 16, an exhalation check valve 30 and into an exhalation chamber 34.
  • a pressure relief valve 32 is provided for the exhalation tube.
  • Exhaled air accumulates in the exhalation chamber 34 and eventually flows through a scrubber assembly 36 which removes carbon dioxide from the exhausted air.
  • the scrubber 36 has opposed filter screens with a soda/lime mixture therebetween that chemically reacts with the carbon dioxide from the exhaled air to form calcium and sodium carbonate and thereby removes the carbon dioxide from the exhaled air. Thereafter the carbon dioxide-free and oxygen-poor exhaled air flows into a return chamber 38 and it is eventually returned to the pressure regulator 26 through a return port 40 having a return port check valve 42.
  • the exhaled air is then mixed with the oxygen-rich gas from the supply 18 in the proper ratio to provide breathable air to the inhalation tube 14 and eventually to the user through the face mask 12.
  • the ratio of exhaled air to oxygen rich air is approximately 4 or 5 to 1.
  • the regulator 26 both controls the flow of high pressure gas and mixes it with the carbon dioxide-free exhaled air to supply the resulting mixture of oxygen enriched air to the user of the apparatus 10 upon breathing demand of the user by inhaling and exhaling.
  • the regulator 26 has a demand diaphragm and valve assembly disposed in a chamber 60 for mixing the pressurized gas and exhaled air to produce oxygen enriched air to be supplied to the mask 12.
  • the pressure regulator 26 has a housing 44 with a cover 45 secured thereto by any suitable means such as cap screws 45a.
  • the housing 44 has a high pressure inlet 46 that receives pressurized gas through the hose 25 from the supply 18.
  • a valve assembly bushing 48 has a poppet valve 50 for opening and closing the inlet 46 and is operated by a valve stem 52.
  • a seal 48' is provided between the bushing 48 and the housing 44 to prevent air leakage.
  • the valve stem 52 is formed by a stem 52a threaded into a sleeve 52b to the desired height and secured thereto by a thread locking patch 52c.
  • the poppet valve 50 has a loose sliding connection with the sleeve 52b through the extension 52d.
  • the valve stem 52 slides within the bushing 48 and a valve stem guide 54 provided in the bushing and sealed by seals 54' so that as the valve stem 52 reciprocates, the poppet valve 50 opens and closes.
  • poppet valve 50 In normal operation, with on/off valve 20 in the on position and prior to any breathing by the user, poppet valve 50 is yieldably biased in the open position by the pressure of the gas from supply 18.
  • a valve seat 55 is provided in the bushing 48 and is sealed by packing seals 55a, 55b.
  • An opening 55c in the valve seat communicates with the inlet 46 to supply pressurized gas from the supply 18 to the face mask 12 upon opening of the poppet valve 50.
  • the poppet valve 50 is opened and closed by a lever 56 pivotally mounted at one end to the bushing 48 by pins 56' and engaged at the opposite end by a diaphragm 58 through a button 58a secured thereto.
  • lever 56, bushing 48, pins 56', and button 58a form means for operably connecting poppet valve 50 and diaphragm 58.
  • the diaphragm 58 is clamped between the housing 44 and the housing cover 45 and is located in a pressure sensing chamber 60 formed between the housing 44 and the housing cover 45.
  • One side 60a of the pressure sensing chamber 60 is maintained at ambient pressure through ambient port 61.
  • the other side 60b of the pressure sensing chamber 60 is maintained at operating pressure (which is generally 1 inch of water or less) through a pressure sensing port 62 which communicates with the face mask 12.
  • Housing 44 also contains a check valve assembly 64 which is connected to the high pressure inlet 46 by ports 44a, 44b, 44c.
  • the assembly 64 comprises a silicon rubber check valve injector nozzle 64a press fit into a nozzle sleeve 64b that is threaded into an outer sleeve 64c.
  • the outer sleeve 64c is threaded to the housing 44.
  • Packing seals 64' prevent air loss around the assembly 64.
  • check valve assembly 64 forms means for isolating poppet valve 50 from mixing chamber 68 by preventing the flow of exhaled air from mixing chamber 68 to poppet valve 50.
  • the outer sleeve 64c has an opening 64c' communicating with the high pressure ports 44a, 44b, 44c to supply high pressure gas from the inlet 46 to the face mask 12.
  • the flexible and flattened or conical end 66 of the nozzle 64a normally remains closed until high pressure gas from the inlet 46 flows through the nozzle 64a forcing the conical end 66 open so that the high pressure gas may flow to a mixing chamber 68.
  • the open end of the nozzle sleeve 64b limits the opening of end 66 of the nozzle 64a to prevent damage thereto.
  • Means are provided for limiting the opening of nozzle 64a in order to prevent damage thereto. Those means comprise the open end of the nozzle sleeve 64b which limits the opening of end 66 of the nozzle 64a, thereby ensuring the continued performance of nozzle 64a.
  • a silicon rubber flapper check valve 42 is mounted on a valve housing 43 by a pin 42a.
  • the valve housing 43 is threaded into the housing 44 and packing seals 43a prevent air and pressure loss.
  • the valve housing 43 forms the return port 40 for supplying carbon dioxide-free air to the mixing chamber 68.
  • a conical or flared mixing tube 74 is threaded at its narrow end 74a into the housing 44 adjacent the mixing chamber 68 and at its wide end 74b has an outer diameter forming a narrow passage 76 with the housing 44. Seals 74c are provided to prevent air and pressure loss.
  • the inhalation tube 14 is connected to the housing 44 adjacent the end 74b to provide breathable air to the face mask 12.
  • the face mask 12 is secured over the face of the user and the carrier pack 17 is strapped to the user's back as is known in the art.
  • the on/off valve 20 supplies regulated pressurized gas of approximately 70-100 PSIG as controlled by the pressure reducer 24 through the hose 25 to the inlet 46.
  • the on/off valve 20 is in the off position, the pressure in the chamber 60 is at about 1 inch of water or less, biasing the diaphragm 58 against the lever 56 to close the valve 50.
  • the pressure of the gas from the supply 18 is greater than that in the chamber 60.
  • the mixed breathable air then flows through the inhalation tube 14 to the face mask 12.
  • pressure in the face mask 12 and the inhalation tube 14 decreases. This decrease in pressure is sensed by the port 62 and thus reduces the pressure in chamber 60, allowing the gas pressure from the inlet 46 to open the valve 50 against the bias of the diaphragm 58.
  • Air flow past the flared end 74b of the mixing tube 74 creates a venturi-like effect at the narrow passage 76 wherein the velocity of air flow past the passage 76 causes an additional pressure reduction at the port 62 and thus the chamber 60 to further assist in allowing the valve to open against the bias of the diaphragm 58.
  • the exhaled air travels through the exhalation tube 16 and into the exhalation chamber 34.
  • air within inhalation tube 14 is pressurized which increases the pressure sensed by the sensing port 62 and the diaphragm 58 in the pressure sensing chamber 60.
  • the diaphragm 58 is forced to the right (as viewed in FIG. 2), which pivots the lever 56 to close the valve 50 to shut off the flow of air from the high pressure hose 25.
  • air in the inhalation tube 14 flows to the face mask 12 causing a pressure decrease initiating another inhalation cycle of the regulator.
  • the poppet valve 50 functions without the use of any mechanical springs, eliminating the possibility of failure of the poppet valve 50, thus eliminating the need for a by-pass.
  • the elimination of springs in the poppet valve 50 ensures faster response to pressure changes due to breathing demands of the user.
  • the poppet valve 50 is isolated from the exhaled air by the check valve injector nozzle 64a which prevents the poppet valve 50 and lever from becoming contaminated by water vapor and cleaning solution.

Landscapes

  • Health & Medical Sciences (AREA)
  • Pulmonology (AREA)
  • Emergency Medicine (AREA)
  • General Health & Medical Sciences (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Respiratory Apparatuses And Protective Means (AREA)
US08/376,084 1993-06-01 1995-01-20 Spring-free pressure regulator with structure isolating exhaled air from valve Expired - Lifetime US5787883A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US08/376,084 US5787883A (en) 1993-06-01 1995-01-20 Spring-free pressure regulator with structure isolating exhaled air from valve

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US7055593A 1993-06-01 1993-06-01
US08/376,084 US5787883A (en) 1993-06-01 1995-01-20 Spring-free pressure regulator with structure isolating exhaled air from valve

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US7055593A Continuation 1993-06-01 1993-06-01

Publications (1)

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US08/376,084 Expired - Lifetime US5787883A (en) 1993-06-01 1995-01-20 Spring-free pressure regulator with structure isolating exhaled air from valve

Country Status (5)

Country Link
US (1) US5787883A (de)
EP (1) EP0631795B1 (de)
JP (1) JPH07553A (de)
CA (1) CA2122522A1 (de)
DE (1) DE69407221T2 (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040089302A1 (en) * 2000-11-02 2004-05-13 Foss Nicholas John Breathing apparatus
US20050016537A1 (en) * 2003-07-25 2005-01-27 Cressi-Sub S.P.A. Second-stage regulator for scuba divers
US20070163591A1 (en) * 2006-01-13 2007-07-19 Ross Julian T Method and system for providing breathable air in a closed circuit
US20110162731A1 (en) * 2010-01-04 2011-07-07 Paul Califano Micro-regulator device
US9038611B2 (en) 2011-11-14 2015-05-26 Ford Global Technologies, Llc NOx feedback for combustion control

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB0014713D0 (en) 2000-06-16 2000-08-09 3M Innovative Properties Co Pressure regulator for a respirator system
ES2897489T3 (es) 2010-06-17 2022-03-01 Hayashibara Co Método de producción de polvo que contiene pululano
KR102014513B1 (ko) * 2017-04-06 2019-08-26 주식회사 파로시스템 산소순환호흡장치
KR102213155B1 (ko) * 2019-08-27 2021-02-08 주식회사 다니엘 공기청정기능을 구비한 비상호흡장치
CN116608533B (zh) * 2023-07-17 2023-10-10 廊坊康平空调制造有限公司 一种大型机库空气隔离系统及其使用方法

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB799635A (en) * 1953-12-19 1958-08-13 Auergesellschaft Ag Improvements in closed circuit breathing apparatus
US3952773A (en) * 1974-01-29 1976-04-27 Dragerwerk Aktiengesellschaft Breathing gas supply controller
US4186735A (en) * 1977-04-21 1980-02-05 Flood Michael G Breathing apparatus
US4299216A (en) * 1979-10-17 1981-11-10 The United States Of America As Represented By The Secretary Of The Interior Self-contained closed circuit breathing apparatus having a balanced breathing resistance system
US4334532A (en) * 1979-06-21 1982-06-15 Chubb Panorama Limited Valves and breathing apparatus incorporating such valves
US4337766A (en) * 1980-05-21 1982-07-06 Chubb Panorama Limited Valves
US4498470A (en) * 1982-01-28 1985-02-12 Dragerwerk Ag Respirator having circulating breathing gas
US4606340A (en) * 1983-07-14 1986-08-19 Figgie International Inc. Combined pressure compensating exhalation and anti-suffocation valve
US4640277A (en) * 1984-05-17 1987-02-03 Texas College Of Osteopathic Medicine Self-contained breathing apparatus
US4682591A (en) * 1985-05-02 1987-07-28 Pneupac Limited Resuscitator/ventilator
US4750485A (en) * 1985-08-05 1988-06-14 Respirator Research Ltd. Portable emergency breathing apparatus
US4774942A (en) * 1987-08-28 1988-10-04 Litton Systems, Inc. Balanced exhalation valve for use in a closed loop breathing system
US4856507A (en) * 1987-04-15 1989-08-15 Intertechnique Two main piloted valves demand regulator for aviators
US4879998A (en) * 1987-08-28 1989-11-14 Litton Systems, Inc. Balanced exhalation valve for use in a closed loop breathing system
US5036841A (en) * 1991-02-22 1991-08-06 Computer Assisted Engineering Self contained closed circuit breathing apparatus

Family Cites Families (2)

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Publication number Priority date Publication date Assignee Title
GB349752A (de) * 1929-05-25 1931-06-04 Otto Heinrich Draeger
DE1173342B (de) * 1960-09-02 1964-07-02 Draegerwerk Ag Atemschutzgeraet mit Kreislauf der Atemluft und lungengesteuertem Atemgaszufuehrungsventil

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB799635A (en) * 1953-12-19 1958-08-13 Auergesellschaft Ag Improvements in closed circuit breathing apparatus
US3952773A (en) * 1974-01-29 1976-04-27 Dragerwerk Aktiengesellschaft Breathing gas supply controller
US4186735A (en) * 1977-04-21 1980-02-05 Flood Michael G Breathing apparatus
US4334532A (en) * 1979-06-21 1982-06-15 Chubb Panorama Limited Valves and breathing apparatus incorporating such valves
US4299216A (en) * 1979-10-17 1981-11-10 The United States Of America As Represented By The Secretary Of The Interior Self-contained closed circuit breathing apparatus having a balanced breathing resistance system
US4337766A (en) * 1980-05-21 1982-07-06 Chubb Panorama Limited Valves
US4498470A (en) * 1982-01-28 1985-02-12 Dragerwerk Ag Respirator having circulating breathing gas
US4606340A (en) * 1983-07-14 1986-08-19 Figgie International Inc. Combined pressure compensating exhalation and anti-suffocation valve
US4640277A (en) * 1984-05-17 1987-02-03 Texas College Of Osteopathic Medicine Self-contained breathing apparatus
US4682591A (en) * 1985-05-02 1987-07-28 Pneupac Limited Resuscitator/ventilator
US4750485A (en) * 1985-08-05 1988-06-14 Respirator Research Ltd. Portable emergency breathing apparatus
US4856507A (en) * 1987-04-15 1989-08-15 Intertechnique Two main piloted valves demand regulator for aviators
US4774942A (en) * 1987-08-28 1988-10-04 Litton Systems, Inc. Balanced exhalation valve for use in a closed loop breathing system
US4879998A (en) * 1987-08-28 1989-11-14 Litton Systems, Inc. Balanced exhalation valve for use in a closed loop breathing system
US5036841A (en) * 1991-02-22 1991-08-06 Computer Assisted Engineering Self contained closed circuit breathing apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040089302A1 (en) * 2000-11-02 2004-05-13 Foss Nicholas John Breathing apparatus
US20050016537A1 (en) * 2003-07-25 2005-01-27 Cressi-Sub S.P.A. Second-stage regulator for scuba divers
US8166974B2 (en) * 2003-07-25 2012-05-01 Cressi-Sub S.P.A. Second-stage regulator for scuba divers
US20070163591A1 (en) * 2006-01-13 2007-07-19 Ross Julian T Method and system for providing breathable air in a closed circuit
US20110162731A1 (en) * 2010-01-04 2011-07-07 Paul Califano Micro-regulator device
US9038611B2 (en) 2011-11-14 2015-05-26 Ford Global Technologies, Llc NOx feedback for combustion control

Also Published As

Publication number Publication date
EP0631795A1 (de) 1995-01-04
JPH07553A (ja) 1995-01-06
CA2122522A1 (en) 1994-12-02
EP0631795B1 (de) 1997-12-10
DE69407221T2 (de) 1998-07-09
DE69407221D1 (de) 1998-01-22

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